moved caching to middleware. implemented a response writer intercept …

…strategy. the cacher interface needs to be thought about a bit more. #96

cache/cache.go

@@ -7,9 +7,10 @@ import (
 
 //	Cacher defines a cache back end
 type Cacher interface {
-	Read(key string) (io.Reader, error)
-	Write(key string, value io.Reader) error
+	Get(key string) (io.Reader, error)
+	Set(key string, value io.Reader) error
 	Purge(key string) error
+	GetWriter(key string) (io.Writer, error)
 }
 
 // InitFunc initilize a cache given a config map.

cache/filecache/filecache.go

@@ -57,13 +57,13 @@ type Filecache struct {
 	Basepath string
 }
 
-func (fc *Filecache) Read(key string) (io.Reader, error) {
+func (fc *Filecache) Get(key string) (io.Reader, error) {
 	path := filepath.Join(fc.Basepath, key)
 
 	return os.Open(path)
 }
 
-func (fc *Filecache) Write(key string, value io.Reader) error {
+func (fc *Filecache) Set(key string, value io.Reader) error {
 	var err error
 
 	//	build our filepath
@@ -90,6 +90,21 @@ func (fc *Filecache) Write(key string, value io.Reader) error {
 	return nil
 }
 
+func (fc *Filecache) GetWriter(key string) (io.Writer, error) {
+	var err error
+
+	//	build our filepath
+	path := filepath.Join(fc.Basepath, key)
+
+	//	the key can have a directory syntax so we need to makeAll
+	if err = os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
+		return nil, err
+	}
+
+	//	create the file
+	return os.Create(path)
+}
+
 func (fc *Filecache) Purge(key string) error {
 	path := filepath.Join(fc.Basepath, key)
 

server/handle_map_zxy.go

@@ -1,9 +1,7 @@
 package server
 
 import (
-	"bytes"
 	"fmt"
-	"io"
 	"log"
 	"net/http"
 	"strconv"
@@ -116,29 +114,6 @@ func (req HandleMapZXY) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		//	check if we have a cache backend setup
-		if Cache != nil {
-			key := fmt.Sprintf("/%v/%v/%v.pbf", req.z, req.x, req.y)
-			cachedTile, err := Cache.Read(key)
-			if err != nil {
-				//	TODO: this should be a debug warning
-				//	log.Printf("cache err: %v", err)
-			} else {
-				//	TODO: how configurable do we want the CORS policy to be?
-				//	set CORS header
-				w.Header().Add("Access-Control-Allow-Origin", "*")
-
-				//	mimetype for protocol buffers
-				w.Header().Add("Content-Type", "application/x-protobuf")
-
-				//	communicate the cache is being used
-				w.Header().Add("Tegola-Cache", "HIT")
-
-				io.Copy(w, cachedTile)
-				return
-			}
-		}
-
 		//	new tile
 		tile := tegola.Tile{
 			Z: req.z,
@@ -177,7 +152,7 @@ func (req HandleMapZXY) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 					}
 					if err != nil {
 						//	TODO: should we return an error to the response or just log the error?
-						//	we can't just write to the response as the waitgroup is going to write to the respons as well
+						//	we can't just write to the response as the waitgroup is going to write to the response as well
 						log.Printf("Error Getting MVTLayer for tile Z: %v, X: %v, Y: %v: %v", tile.Z, tile.X, tile.Y, err)
 						return
 					}
@@ -243,18 +218,15 @@ func (req HandleMapZXY) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		if len(pbyte) > MaxTileSize {
 			log.Printf("tile z:%v, x:%v, y:%v is rather large - %v", tile.Z, tile.X, tile.Y, len(pbyte))
 		}
-
-		//	check if we have a cache
-		if Cache != nil {
-			key := fmt.Sprintf("/%v/%v/%v.pbf", req.z, req.x, req.y)
-			r := bytes.NewReader(pbyte)
-
-			//	write to our cache
-			if err := Cache.Write(key, r); err != nil {
-				log.Printf("cache err: %v", err)
+		/*
+			//	check if we have a cache
+			if Cache != nil {
+				//	write to our cache using the url path as the key
+				if err := Cache.Set(r.URL.Path, bytes.NewReader(pbyte)); err != nil {
+					log.Printf("cache err: %v", err)
+				}
 			}
-		}
-
+		*/
 		//	log the request
 		L.Log(logItem{
 			X:         tile.X,

server/server.go

@@ -59,7 +59,7 @@ func Start(port string) {
 	group.UsingContext().Handler("OPTIONS", "/capabilities/:map_name", HandleMapCapabilities{})
 
 	//	map tiles
-	group.UsingContext().Handler("GET", "/maps/:map_name/:z/:x/:y", HandleMapZXY{})
+	group.UsingContext().Handler("GET", "/maps/:map_name/:z/:x/:y", CacheHandler(HandleMapZXY{}))
 	group.UsingContext().Handler("OPTIONS", "/maps/:map_name/:z/:x/:y", HandleMapZXY{})
 	group.UsingContext().Handler("GET", "/maps/:map_name/style.json", HandleMapStyle{})